How often do you charge your Di2

How long does a full charge last on your Di2? What % discharge do you top it up? Do you monitor it with your Garmin? Now, I know it depends on how much use it gets, but just looking for a ball park figure. Thanks.

Comments

  • ibr17xvii
    ibr17xvii Posts: 1,065
    Having had Di2 not that long I’m interested in this as well.

    I did just over 1300 miles before I had to charge it & have to say I was expecting more. Don’t think I shift any more than the average rider but everyone’s different I guess.

    It seemed to be a fair time on green then went to red quite suddenly. Front mech wasn’t shifting so I believe that’s less than 10%.

    I don’t have the wireless unit so just going off the pressing the shifter button & seeing the lights on the junction box so not as accurate but still thought it would last longer all the same.
  • dannbodge
    dannbodge Posts: 1,152
    I charge it when my wahoo tells me to (15% iirc)
  • Monitor with my garmin ,soon as I get the 20% warning .
  • ibr17xvii said:

    Having had Di2 not that long I’m interested in this as well.

    I did just over 1300 miles before I had to charge it & have to say I was expecting more. Don’t think I shift any more than the average rider but everyone’s different I guess.

    It seemed to be a fair time on green then went to red quite suddenly. Front mech wasn’t shifting so I believe that’s less than 10%.

    I don’t have the wireless unit so just going off the pressing the shifter button & seeing the lights on the junction box so not as accurate but still thought it would last longer all the same.

    You'll be surprised by hw many shifts you do in a ride .
    I've seen on a 25 mile ride around 250 wit 2000ft elevation .
    I believe they state around 1500 miles for a charge iirc so your not to far off if its a bit hilly
  • I have one of the earlier versions (2013 Ultegra) which Shimano claim should be good for 1000 km. I found that the low battery warning comes at around 1000 miles, in other words well in excess of Shimano's claims. This may be because I shift less than expected - I live in a flat area so rarely need to shift to the little ring. Front shifting is said to be a bigger drain on the battery.

    However, about 5 years ago, following a crash, I found that the battery now discharges itself completely, after about 2 weeks, even if I have not ridden the bike during that time. It seems the system is continuing to draw power even when not being used. Two different bike shops have failed to identify and cure the problem. A firmware update did not help. I am therefore having to charge the battery frequently, and carry a spare with me, in case it dies on a ride. While this is not a major problem, it is irritating, so if anyone knows a solution, I would be interested!
  • Sutton_Rider
    Sutton_Rider Posts: 493
    Interesting Oblongomaculatus, Like you I live and cycle in a flat area (The Fens) so I don't change the front rings much. From a fully charged battery its taking around 50 days to go down to 50% (according to my Garmin). Once it gets to 70% the speed of the drain is getting faster. Its not a linear curve.

    From what you said I take it the the drain is the same which ever battery you are using, if so you can rule those out. You also say like me you don't change the front rings. Try disconnecting the FD and see if that makes a difference. Then disconnect the left SDI and so on to eliminate each unit in turn. As the battery goes flat quite quickly this trial and error shouldn't take too long.
  • ibr17xvii
    ibr17xvii Posts: 1,065

    ibr17xvii said:

    Having had Di2 not that long I’m interested in this as well.

    I did just over 1300 miles before I had to charge it & have to say I was expecting more. Don’t think I shift any more than the average rider but everyone’s different I guess.

    It seemed to be a fair time on green then went to red quite suddenly. Front mech wasn’t shifting so I believe that’s less than 10%.

    I don’t have the wireless unit so just going off the pressing the shifter button & seeing the lights on the junction box so not as accurate but still thought it would last longer all the same.

    You'll be surprised by hw many shifts you do in a ride .
    I've seen on a 25 mile ride around 250 wit 2000ft elevation .
    I believe they state around 1500 miles for a charge iirc so your not to far off if its a bit hilly

    Yeah you’re right & I do get some hilly rides in pretty regularly.

    I’ve nothing to compare it to having not had Di2 before but I just expected it to last longer I guess.

    Obviously charging it up every couple of months isn’t a hardship though.
  • ibr17xvii
    ibr17xvii Posts: 1,065

    From a fully charged battery its taking around 50 days to go down to 50% (according to my Garmin). Once it gets to 70% the speed of the drain is getting faster. Its not a linear curve.


    This is 100% my limited experience as well.


  • From what you said I take it the the drain is the same which ever battery you are using, if so you can rule those out. You also say like me you don't change the front rings. Try disconnecting the FD and see if that makes a difference. Then disconnect the left SDI and so on to eliminate each unit in turn. As the battery goes flat quite quickly this trial and error shouldn't take too long.

    Yes, it's the same with both batteries. I bought the second one believing the original battery was beginning to fail, causing it to need more frequent recharging, only to find the second one behaving the same way.

    I'd like to try the process of elimination you suggest (while leaving the bike idle). I can see where the wires plug into the derailleurs but I'm not sure where to disconnect the shifters

    I suspect it's most likely to be the right shifter; in the crash I mentioned the whole brake lever unit was pushed round about 45°, which I think caused the wire to unplug, as that shifter wasn't functional, though the other one was. But as I left it to the bike shop to sort out (as well as checking over the frame for damage, and trueing the front wheel) I'm not familiar with the innards of the STI's.
  • Sutton_Rider
    Sutton_Rider Posts: 493


    This may help Oblongomaculatus the other end may go to a junction box, you can disconnect it there.

    ibr17xvii - Thanks, it looks like its working OK then. What started this off was the battery was at 60%, the bike was not used for 3 days by which time it had gone down to 30%. I'll keep checking it for the next couple of days and see what happens.


  • This may help Oblongomaculatus the other end may go to a junction box, you can disconnect it there.

    Oh yes, I see them now. I was looking under the top part of the hood. I see each one has two ports, with the wire going into the top one. In the lower one, there is what looks one of the caps that goes on the end of the wire. It's loose in the left shifter, but clicked in on the right. What are they for?

    Sorry for all the questions; I've never looked closely before so despite owning the bike for 8 years I'm seeing new things!
  • Sutton_Rider
    Sutton_Rider Posts: 493
    They are just blanking plugs and will not effect the operation whether in out or loose.
  • mazwmb
    mazwmb Posts: 22



    From what you said I take it the the drain is the same which ever battery you are using, if so you can rule those out. You also say like me you don't change the front rings. Try disconnecting the FD and see if that makes a difference. Then disconnect the left SDI and so on to eliminate each unit in turn. As the battery goes flat quite quickly this trial and error shouldn't take too long.

    Yes, it's the same with both batteries. I bought the second one believing the original battery was beginning to fail, causing it to need more frequent recharging, only to find the second one behaving the same way.

    I'd like to try the process of elimination you suggest (while leaving the bike idle). I can see where the wires plug into the derailleurs but I'm not sure where to disconnect the shifters

    I suspect it's most likely to be the right shifter; in the crash I mentioned the whole brake lever unit was pushed round about 45°, which I think caused the wire to unplug, as that shifter wasn't functional, though the other one was. But as I left it to the bike shop to sort out (as well as checking over the frame for damage, and trueing the front wheel) I'm not familiar with the innards of the STI's.
    I had a right hand shifter cause battery drain, I charged it every other week. I found it was the right shifter by disconnecting it totally and using synchro shift with the left shifter and the battery then lasted a lot longer.
    Out of interest I’m going to note how long it goes between charges.
  • I have one of the earlier versions (2013 Ultegra) which Shimano claim should be good for 1000 km. I found that the low battery warning comes at around 1000 miles, in other words well in excess of Shimano's claims. This may be because I shift less than expected - I live in a flat area so rarely need to shift to the little ring. Front shifting is said to be a bigger drain on the battery.

    However, about 5 years ago, following a crash, I found that the battery now discharges itself completely, after about 2 weeks, even if I have not ridden the bike during that time. It seems the system is continuing to draw power even when not being used. Two different bike shops have failed to identify and cure the problem. A firmware update did not help. I am therefore having to charge the battery frequently, and carry a spare with me, in case it dies on a ride. While this is not a major problem, it is irritating, so if anyone knows a solution, I would be interested!

    I've seen similar issues and it was a fault in the 4 way junction ( JC41) THE Port for the FD was drawing power causing it to shift even when not in use
  • I have one of the earlier versions (2013 Ultegra) which Shimano claim should be good for 1000 km. I found that the low battery warning comes at around 1000 miles, in other words well in excess of Shimano's claims. This may be because I shift less than expected - I live in a flat area so rarely need to shift to the little ring. Front shifting is said to be a bigger drain on the battery.

    However, about 5 years ago, following a crash, I found that the battery now discharges itself completely, after about 2 weeks, even if I have not ridden the bike during that time. It seems the system is continuing to draw power even when not being used. Two different bike shops have failed to identify and cure the problem. A firmware update did not help. I am therefore having to charge the battery frequently, and carry a spare with me, in case it dies on a ride. While this is not a major problem, it is irritating, so if anyone knows a solution, I would be interested!

    I've seen similar issues and it was a fault in the 4 way junction ( JC41) THE Port for the FD was drawing power causing it to shift even when not in use
    Should say it wasn't fully shifting it was just a very slight click coming from the FD
  • pilot_pete
    pilot_pete Posts: 2,120
    Charge mine about every thousand miles. I monitor charge level on my Garmin and when it hits 25% I charge it up.

    Regarding battery drain, a number of issues come to mind. Search Google and YouTube for lots of possibilities. As you crashed it’s possible to be related to some sort of damage. It could be a damaged lever, but it can also be a wiring fault and even a derailleur end stop adjustment. This guide is a good starting place; https://bettershifting.com/how-to-troubleshoot-di2-battery-drain-issues/

    Ideally get it hooked up to the diagnostics tool SM-PCE02. They are reasonably expensive, but in the big scheme of things a di2 groupset is an expensive thing. I invested in one a year or two back as I run two bikes with di2. I haven’t had to use it much but did recently diagnose a wiring fault causing my battery to drain.

    The beauty of the diagnostic tool is you can plug it in to each component individually and test it, including a battery drain test.

    But failing getting the tool, try the easy things first - make sure it’s not derailleur end stop adjustment and then just use trial and error - unplug one item and see if you still get the drain. Plug it back in and try another and so on. This could help isolate a faulty component or the wiring to that component.
  • Sutton_Rider
    Sutton_Rider Posts: 493
    Thanks for your input Pete, I've got a PCE02 and have run the system through a couple of times, but no fault found. I've been keeping track of the battery state since a full charge. It took 50 days to drop to 40% (According to the edge 1000), but it wasn't a linear discharge. At 30 days in it was still at 90% -9 days later 80% then 3 days down to 70% another 3 days 60% and so on. I've now done a full re-charge and I'm going to repeat the test and see how it compares. I've checked all the other things like end stops and again NFF.
  • Thanks for the suggestions. I guess I won't be investing in a PCE02, though I might ask my Specialized dealer if they have one. That was one of the bike shops that failed to diagnose the problem, but it was a while ago, so maybe they didn't have one then.

    Trevor, I don't think that's what's happening with mine. There's no noise anywhere, ie no phantom shifting.

    mazwmb, I can't use your solution, I don't think my Di2 has synchoshift, as I said it's 1st generation Ultegra from 2013.

    pilot Pete, that sounds promising, not something I'd considered. Are you saying if the derailleur end stop isn't adjusted correctly it might be causing a tiny power drain, emptying the battery over time (mine drains so completely there isn't even any power left to light the warning LED's)? To be honest, I'm not very technical, I'm not sure what the derailleur end stop is! I've had a quick took at the page you linked to, seems like it might be helpful. I'll have a proper look when I've got more time and have the bike in front of me.
  • dennisn
    dennisn Posts: 10,601
    I don't have electronic shifting but am wondering just how much trouble it is to "charge up"? Also, why not charge it more often rather than wait for it to tell you it's almost dead?
  • Sutton_Rider
    Sutton_Rider Posts: 493
    edited July 2021
    It's as easy as charging your phone or any other gismo. No one is suggesting leaving a charge until the last second, you charge it when needed. My original question was how long does a full charge last.
  • dennisn
    dennisn Posts: 10,601

    It's as easy as charging your phone or any other gismo. No one is suggesting leaving a charge until the last second, you charge it when needed. My original question was how long does a full charge last.

    There my not be an answer to your question. Too many variables. If Shimano doesn't know or see fit to tell you then I would assume that the smart thing to do would be charge it regularly and often. can't hurt. After all you don't drive your car till it's empty.
  • Sutton_Rider
    Sutton_Rider Posts: 493
    Dennisn please read my original post. You are right there are too many variables, but I was looking for a ball park figure. Just to see what others are doing. However, you are wrong saying it can't hurt charging regularly and often. These batteries do not have an infinite number of charge discharge cycles.
  • mully79
    mully79 Posts: 904
    lithium ion batteries are all similar.
    They last a maximum amount of charge cycles if looked after.
    Looked after includes not overcharging (ie overnight) and definitely includes not fully discharging. An empty lithium ion battery is not really empty as its a software limit. They become unstable below a certain level and cant be recovered.
    Thats why your phone dies forever when you leave it in the car with an empty battery in winter.
  • oblongomaculatus
    oblongomaculatus Posts: 616
    edited July 2021
    mully79 said:

    lithium ion batteries are all similar.
    They last a maximum amount of charge cycles if looked after.
    Looked after includes not overcharging (ie overnight) and definitely includes not fully discharging. An empty lithium ion battery is not really empty as its a software limit. They become unstable below a certain level and cant be recovered.
    Thats why your phone dies forever when you leave it in the car with an empty battery in winter.

    I've read conflicting advice about lithium ion batteries (in general, not specifically Di2). Some advice is to wait until they are nearly empty before charging; that frequently topping up shortens the life. Other advice has been it makes no difference. I don't think my Di2 battery can be overcharged, though. It gets warm when charging but cools off when finished (and the indicator light goes off) so I'd guess the charger stops supplying a charge at that point.

    That's the first I've heard of a mobile phone battery dying permanently if left uncharged for a long time. Are you sure that's right? It may be true of lead-acid batteries. After my Dad died, his mobility scooter was left uncharged for several months. When I came to sell it I found I couldn't charge the battery. With my Di2 discharging itself completely even when left idle, I have been leaving the battery on, only taking it off and charging it when I plan to ride.

    So far the battery charges normally, but maybe I should be removing it after each ride, though I'm reluctant to do that as I've also had some issues with the fitting, mounted below the bottom bracket, working loose, presumably because of the battery being removed more often than intended (The whole lot fell off during a ride recently; I wasn't able to fix it by the road and had to ride home on one gear).

    My policy, before my Di2 developed the fault I've described, was to wait until the indicator shows 25%, and then charge it. I'm guessing there would actually have been several weeks of riding left at that point, but didn't want to risk it dying mid ride. Shimano says even when the indicator is showing near empty (flashing red) you should still have about 50 rear shifts left, enough to get you home.
  • darrell1967
    darrell1967 Posts: 470
    I’ve got Di2 on my 2.5 year old Boardman. I do about 5000 miles a year on it in all types of road conditions and I don’t think I’ve charged the battery more than 8 times.

    In all honesty it’s something you really do t need to think about.